In the UK, has a dukedom ever been removed from a person?

There hasn't been a case of a person being dispossessed of their hereditary peerage since the Acts of Union, but there have been several in the seperate kingdoms of England and Scotland before that.  All of these dispossession occurred due to acts of treason.  Under law dispossessed peerages are regarded as extinct. 

The Titles Deprivation Act created a situation different to a dispossession, in that the 1917 law treats the title as extant, but prohibits holders from sitting in the House of Lords. 

Quite a lot actually - most often when their heads were removed from their bodies.

"Sniff, sob" Yes, I was once a peer of the realm but, now I'm just a, Sir Prince. Oh how I miss those days of "Sir Prince Duke Kenny of Flobadob".Will I ever hear again, those greetings from the peasants and pondlife, "The our great and glorious leader, font of all knowledge and member of the RAC, Sir Prince Duke Kenny of Flobadob?" CIA, KGB (with bar) MI5 (withdrawn from the bar) and all round good egg what, what?

Yes.  In 1917, two German princelings had the titles Duke of Albany and  Duke of Cumberland.  They were stripped of their titles for fighting for Germany in WW1.  At the same time, British royalty stopped using their German titles and the House of Saxe-Coburg Gotha became the House of Windsor.   The Dukes of Norfolk have had their dukedom removed on a number of occasions for having a different religion to the monarch.  However it was reinstated in 1660 and they've been able to hang on to it ever since.

Yes.  A few.  The main ones were due to them being German and Britain being at war with Germany,.

https://en.wikipedia.org/wiki/Titles_Deprivation_A...

King George V removed titles from two dukes who sided with Germany during the First World War under the Titles Deprivation Act 1917.

Yes. George Plantagenet, Duke of Clarence, had his dukedom stripped of him and died in the Tower of London, his being but one example of the many dukedoms, along with all manner of titles from king down, that were stripped and restored and stripped again and restored again and stripped again in the back and forth between the Plantagenets and Plantagenet loyalists and the Tudors and Tudor loyalists throughout the Wars of the Roses.